A transmitting/receiving system includes a transmitting apparatus that generate modulated signals each containing a broadband signal component and a narrowband signal component, and transmits the modulated signals to the outside and a receiving device that receives the modulated signals via at least three receiving antennas. The receiving device includes a signal processing system that processes the broadband signal component contained in the modulated signal and a received-strength detecting system that processes the narrowband signal component contained in the modulated signal.
